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The Escherichia coli MarA protein regulates the ycgZ-ymgABC operon to inhibit biofilm formation.

ABSTRACT: The Escherichia coli marRAB operon is a paradigm for chromosomally encoded antibiotic resistance. The operon exerts its effect via an encoded transcription factor called MarA that modulates efflux pump and porin expression. In this work, we show that MarA is also a regulator of biofilm formation. Control is mediated by binding of MarA to the intergenic region upstream of the ycgZ-ymgABC operon. The operon, known to influence the formation of curli fibres and colanic acid, is usually expressed during periods of starvation. Hence, the ycgZ-ymgABC promoter is recognised by ?³⁸ (RpoS)-associated RNA polymerase (RNAP). Surprisingly, MarA does not influence ?³⁸ -dependent transcription. Instead, MarA drives transcription by the housekeeping ?⁷⁰ -associated RNAP. The effects of MarA on ycgZ-ymgABC expression are coupled with biofilm formation by the rcsCDB phosphorelay system, with YcgZ, YmgA and YmgB forming a complex that directly interacts with the histidine kinase domain of RcsC.

SUBMITTER: Kettles RA

PROVIDER: S-EPMC6900184 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature

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The Escherichia coli MarA protein regulates the ycgZ-ymgABC operon to inhibit biofilm formation.

Kettles Rachel A RA Tschowri Natalia N Lyons Kevin J KJ Sharma Prateek P Hengge Regine R Webber Mark A MA Grainger David C DC

Molecular microbiology 20190929 5

The Escherichia coli marRAB operon is a paradigm for chromosomally encoded antibiotic resistance. The operon exerts its effect via an encoded transcription factor called MarA that modulates efflux pump and porin expression. In this work, we show that MarA is also a regulator of biofilm formation. Control is mediated by binding of MarA to the intergenic region upstream of the ycgZ-ymgABC operon. The operon, known to influence the formation of curli fibres and colanic acid, is usually expressed du ...[more]

PMID: 31518447

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The Escherichia coli MarA protein regulates the ycgZ-ymgABC operon to inhibit biofilm formation.

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The Escherichia coli MarA protein regulates the ycgZ-ymgABC operon to inhibit biofilm formation.

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